A manual device for delivering viscous fluid is known from DE 31 03 610 A1, which is equipped with a rotation drive unit that is coupled to a gear assembly. Two piston rods having pistons are moved by way of the gear assembly and each act on a container that contains a viscous fluid of a multicomponent molding compound. The container is connected at its end opposite the piston to a mixing nozzle. The containers can each be removed from the manual device and exchanged. The gear assembly, to which the piston rod with the piston is connected, is driven by an electric motor provided in the manual device or by compressed air. In order to retract the piston into a starting position, a coupling/clutch is provided in each case between the piston rod and the gear assembly. This manual device is extremely heavy and because of the necessary compressed air seals, among other things, expensive to manufacture.
Furthermore, a stationary table device is known that has in a housing a piston to deliver the viscous fluid of the multicomponent molding compound as well as a gear assembly and rotation drive unit powering the piston via the gear assembly. The rotational drive unit can be controlled manually with regard to its rotational speed by way of a rotary switch seated in the housing. The amount of molding compound delivered per unit time is regulated by way of the rotational speed.
A disadvantage with such a design, when used in the dental field, is the inability for the device to be used directly on the patient, for instance, when an impression molding compound for dental purposes is to be delivered and mixed.
Furthermore, the dentist requires both hands for operating this device, one hand for the rotary switch and one hand for the bowl in which the mixed impression molding compound is placed. The handling is therefore extremely cumbersome and unfavorable for the field of dentistry and dental technician work.
A hand and angle piece for dental treatment purposes is known from DE 31 22 061 A1 that features a battery, an electric motor and a switch for turning the motor on and off. The hand and angle piece can be connected via a coupling/transmission to dental tools such as a drill, the tool comprising the opposing piece for the coupling of the hand and angle piece.
In DE 31 29 348 A1, a metering syringe is disclosed, which features a piston rod and piston arranged at the end of the piston rod in the cylindrical housing. The piston rod is provided with a thread that engages with a nut seated in a guidance part. With the revolution of the nut seated stationary in the guidance part the piston is moved via the piston rod in the housing.